1995 Riviera SC Harmonic Balancer Replacement

[CraigMacTC]

Here is the situation....I replaced my harmonic balancer 7 days ago and that one has gone out. I am hoping that it was just a defective part and am planning on replacing it again, along with the CPS since I'm almost positive that is destroyed this time around. My question is..If the part is not defective what would cause it to fail so quickly? After I installed it, everything was running smooth, pulleys, idle, accelartion. An ideas would be great.

By the way....this is how I felt when replacing my waterpump

[ralfwho]

OK, here is my tale of woe, hopeully someone else will learn from my trials.
Last summer, the engine of my SC Riv 3.8 with 140k miles started making a terrible noise from the general area of the timing gear. So off came the belt tensioning assembly, water pump, and harmonic balancer. Whoa! One DISINTEGRATED harmonic balancer! The rubber that held the two pieces together had shredded and there was about 30 degrees of play between the timing tabs and the hub. I replaced it with a DORMAN (made-in-China) balancer for about $100. Replaced the timing chain, gear, and water pump, as long as I was there. Not a difficult job, just a bit annoying because of the stuff you have to move to get to the bare front cover.
Car ran great, for exactly 405 miles.
Limped home one night and as I creeped up the driveway, it started spewing oil out the front seal all over the place. "This ain't good" I thought. Three months of miserable cold weather and the Riv had to sit on the driveway until three weeks ago when I put together enough will to see what happened.
The answer was pretty quick in coming. When I took off the balancer (remember, made in China for $100) it came out in two chunks. Seems that the hub had fractured at the keyway and this was the cause, I figured, for the "running like crap". The splintered hub must've taken the front seal with it, causing the oil hemorrage. Off came the front cover (in order to replace the front seal) and just for the hell of it I took a real good look at the oil pump, which on the 3800 is driven by the crank, just behind where the balancer sits. Good thing I did. The housing was cracked from the balancer failure and this is where I was losing oil.
I took the balancer back to Lee Auto in Arlington Heights IL and told them my tale. They took the old balancer and gave me a new one, with no questions. Just for the hell of it, I took the new balancer to my machine shop of choice and this is the purpose for my rant.

The NEW BALANCER WAS DEFECTIVE!!!!!!!!!

Seems my machine shop guy Joe teaches at a local jr college and mentioned that the Dorman guy told him these things are failing left and right. So we checked the new one very closely. Not only was the keyway cut too wide, it was cut too shallow on one end; torquing this one on the crankshaft was sure to fracture the hub. Most likely this is what happened to my first replacement balancer - it started to fail as soon as I installed it.

One might be quick to label all stuff from China as crap and I'm not sure I would argue that. Certainly I will never go the cheap route on a mission-critical part again.

Perhaps the better lesson is to very carefully inspect (maybe a better word would be MEASURE) mission-critical parts.

[CraigMacTC]

Thanks for your quick response..the first thing I did after reading it was to check the brand I purchased and sure enough it was a DORMAN!!!! How the this company is surviving is beyond me. I pulled it off and you called it Ralfwho.....fractured at the keyway. Luckily it didn't damage the front seal and the crank sensor is still looking good, still replacing it though. I called the parts store I purchased it from to check on other brands and it's the only one they have available. I will exchange it, crossing my fingers, and if it fails it's to the GM parts shop for me. Thanks again Ralfwho for your tale of woe, I can only hope all 95 Rivy owners come accross this thread.

[HotZ28]

For 25 bucks more, you can get a genuine GM balancer. Why waste any more labor installing inferior parts? The labor alone, will more than justify the cost of the "real thing". Parts that are "honcho in Mexico or China" are nowhere the same quality of materials or machining process. They get it as close as they can and that is good enough for them to sell.

Can you believe that they are making Buicks in China now; not for export yet, but look out they may be coming! In the future, you may be able to buy a new Buick at Pep Boys, displayed on the floor next to the China motor bikes they sell.

[ralfwho]

If you ARE going to use a DORMAN balancer, check the dimensions of the keyway.

If the keyway is not cut long enough, the key will fracture the hub when you torque-down the balancer nut.

It appears that the keyway is cut a bit too shallow on the side closest to the OUTSIDE of the engine. That is, when you install the balancer, the key exerts too much pressure on the slot.